The purpose of the proposed studies is to elucidate the role of variant plasminogens, and other abnormal fibrinolytic pathway components in hypo- and hypercoagulable diseased states which are attributable t the fibrinolytic system. In addition, the role of these abnormal components in the dissolution of fibrin clots will be examined. The kinetic behavior of the fibrinolytic system will be studied in normal plasma and the plasma of patients with sub- and supernormal fibrinoloytic states, both in whole plasma and with purified components. The second phase of the study will explore the significance of surface activation of plasminogen and the kinetics of interaction between plasmin(ogen) and fibrin. This phase will also be devoted to studies on the kinetics of dissolution of fibrin clots in vitro. The possible pathological role of sub- and supernormal fibrinolytic potential in dissolution of fibrin clots will be tested in a purified system, as well as in a plasma milieu.